'They have the same eyes,' commented a fan on Parsons' Instagram post.

Iain Armitage as mini-Sheldon in Young Sheldon and Jim Parsons as original Sheldon in The Big Bang TheoryCBS

Jim Parsons who plays the quirky physicist Sheldon Cooper in The Big Bang Theory, posted a snap with the younger version of his character, to be played by actor Iain Armitage in the spinoff series, Young Sheldon, on social media and fans can't handle the cuteness.

Parsons posted a pic of himself with Armitage from Young Sheldon sets and revealed that the child actor gifted him an ant farm. Both the versions of Sheldon are smiling with an ant farm visible in the frame behind them.

"Thank you, @iainlovestheatre for my ant farm! (It's the blue thing behind us) on set of @youngsheldoncbs," he captioned the Instagram post. Fans have adored the snap of the two actors as one user commented, "Awww, amazing shot guys!! Looking so forward to watching Young Sheldon ~ brilliant idea & I know it will be a brilliant show!! ♡♡♡♡♡"

Speaking about the casting of nine-year-old Sheldon, a fan of Parsons wrote, "You guys look great together, you couldn't have found a better young Sheldon," while another user commented, "They have the same eyes cute!!"

"Awww too cute, you too are adorable," said a Big Bang Theory fan. "That is awesome! I can't wait for the young Sheldon and new season of The Big Bang!!" a comment read. "What a blessing seeing two smart persons happy together and sharing love and friendship. @therealjimparsonsboth of you spread harmony, light and happiness," a user wrote.

The 44-year-old star CBS star gushed about filming Young Sheldon. Parsons, who will be the executive producer and narrate the show, said at the 2017 Television Critics Association press tour, "It was a moving experience for me to see something I've put a decade of my life toward [come to this]."

Parsons also spoke highly of Armitage during the panel. He said, "We have a lot more in common now than I would have had at the same age. I wasn't mature enough at 9. I was not an overly bright child. I was mediocre. I didn't befuddle my parents. That came much later, with my sexuality. Iain is much more in control as a human being than I was."